1 2 static char help[] = "Saves 4by4 block matrix.\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat A; 9 PetscInt i,j; 10 PetscMPIInt size; 11 PetscViewer fd; 12 PetscScalar values[16],one = 1.0; 13 Vec x; 14 15 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 16 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 17 PetscCheck(size == 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,m"Can only run on one processor"); 18 19 /* 20 Open binary file. Note that we use FILE_MODE_WRITE to indicate 21 writing to this file. 22 */ 23 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"4by4",FILE_MODE_WRITE,&fd)); 24 25 PetscCall(MatCreateSeqBAIJ(PETSC_COMM_WORLD,4,12,12,0,0,&A)); 26 27 for (i=0; i<16; i++) values[i] = i; 28 for (i=0; i<4; i++) values[4*i+i] += 5; 29 i = 0; j = 0; 30 PetscCall(MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES)); 31 32 for (i=0; i<16; i++) values[i] = i; 33 i = 0; j = 2; 34 PetscCall(MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES)); 35 36 for (i=0; i<16; i++) values[i] = i; 37 i = 1; j = 0; 38 PetscCall(MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES)); 39 40 for (i=0; i<16; i++) values[i] = i;for (i=0; i<4; i++) values[4*i+i] += 6; 41 i = 1; j = 1; 42 PetscCall(MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES)); 43 44 for (i=0; i<16; i++) values[i] = i; 45 i = 2; j = 0; 46 PetscCall(MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES)); 47 48 for (i=0; i<16; i++) values[i] = i;for (i=0; i<4; i++) values[4*i+i] += 7; 49 i = 2; j = 2; 50 PetscCall(MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES)); 51 52 PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY)); 53 PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY)); 54 PetscCall(MatView(A,fd)); 55 PetscCall(MatDestroy(&A)); 56 57 PetscCall(VecCreateSeq(PETSC_COMM_WORLD,12,&x)); 58 PetscCall(VecSet(x,one)); 59 PetscCall(VecView(x,fd)); 60 PetscCall(VecDestroy(&x)); 61 62 PetscCall(PetscViewerDestroy(&fd)); 63 PetscCall(PetscFinalize()); 64 return 0; 65 } 66